1. Field of the Invention
This invention relates to the Lost Wax Process of casting and more specifically to a process and apparatus for the assembly of a wax tree.
2. Prior Art and Objects
The Lost Wax Process of casting is a widely used and well-know process. Basically, a wax pattern is formed by wax injection molding. Then, a multiplicity of the wax patterns, each of which includes a gate, is affixed to a runner creating a wax tree assembly. Then, ceramic is spread over the wax tree assembly. The resulting ceramic shell is then heated to melt the wax and the wax is thus removed from within the ceramic shell. Molten material, usually a metal, is then poured into the ceramic shell. Upon hardening, the ceramic is broken away and the desired castings are removed from the cast version of the runner.
The Lost Wax Process is a highly labor intensive procedure, but in more recent times, the wax pattern production, ceramic buildup and metal pouring have been successfully automated. The wax tree assembly, however, has remained a labor intensive operation. Furthermore, wax tree assembly requires artistic abilities on the part of the wax tree assembler. Even an experienced and artistic assembler cannot avoid improper connections which result in rejected castings.
It has been recognized that the most desirable fusion between the gate of the wax pattern and the wax runner is a fillet weld which is similar to the well-known fillet welds used in metal welding. However, despite the great need, the technique for readily achieving fillet weld fusion in wax tree assembly has not been previously known.
Various techniques have been proposed to automate the assembly of the wax tree assembly. One proposal, which apparently originated in Japan, places the gate of the wax patterns into a recessed surface of the wax runner and then molten wax is poured into the recessed area to fuse the wax pattern to the runner. The resulting fusion does not provide the desired fillet weld between the runner and the gate of the wax pattern and the poured wax does not possess the quality of the original molded wax of the runner. This method is also a manual operation and it does not appear to be an operation that offers a realistic basis for automation.
Wax Tree Assembly Machines have also been developed both in the United States and in Russia but both attach wax patterns to a runner that is held sideways. This results in potential dripping problems which can damage the wax pattern.
Therefore, it is an object of this invention to develop a process by which a highly acceptable bond between the gate of a wax pattern and a runner can be achieved.
It is a further object of this invention to provide an automated process for connecting the gate of a wax pattern to a runner.
It is a further object of this invention to provide a process for the assembly of wax trees that is economical and dependable.
It is further object of this invention to provide a process for the assembly of wax trees that produces a high rate of acceptable castings.
It is still another object of this invention to provide an apparatus to effectuate the successful operation of an automated process for the assembly of wax tree assemblies.
It is still another object of this invention to provide an apparatus that accurately and repeatedly produces a wax tree assembly.
It is a further object of this invention to provide an apparatus for the production of wax tree assemblies that is durable and dependable.
These and other objects and advantages of the present invention will become apparent to those of ordinary skill in the art as the description thereof proceeds.